Position-retaining device

ABSTRACT

In an initial configuration a device comprises a casing containing: a plurality of beads, a rupturable first container containing one or more isocyanates and a rupturable second container containing one or more polyols, wherein in the final configuration the casing is substantially filled by a polyurethane in which the plurality of beads are embedded. In an intermediate configuration the device is transformed from the initial configuration to a final configuration by rupturing the first container and rupturing the second container so that the one or more isocyanates react with the one or more polyols in a reaction that forms the polyurethane. As the polyurethane is formed during the reaction the polyurethane surrounds the plurality of beads. The device may be molded as the polyurethane is formed in the casing.

BACKGROUND

Field of the Invention

The present invention relates to a moldable position-retaining device.

Related Art

Various outfits and equipment have been used in the fields of medicaltreatment and patient care and welfare for stabilizing and supportinghuman bodies on beds, chairs, inspection and examination devices and thelike. These outfits and equipment have various deficiencies.

SUMMARY

According to a first broad aspect the present invention provides adevice comprising a casing and having: an initial configuration, anintermediate configuration, and a final configuration, wherein in theinitial configuration the casing contains: a plurality of beads, arupturable first container containing one or more isocyanates and arupturable second container containing one or more polyols, wherein inthe final configuration the casing is substantially filled by apolyurethane in which the plurality of beads are embedded, wherein inthe intermediate configuration the device is transformed from theinitial configuration to the final configuration by rupturing the firstcontainer and rupturing the second container so that the one or moreisocyanates react with the one or more polyols in a reaction that formsthe polyurethane, and wherein as the polyurethane is formed during thereaction the polyurethane surrounds the plurality of beads.

According to a second broad aspect, the present invention providesmethod comprising: transforming a position-retaining device from aninitial configuration to an intermediate configuration, and transformingthe position-retaining device from the intermediate configuration to afinal configuration, wherein the in the initial configuration, theposition-retaining device comprises a casing containing: a plurality ofbeads, a rupturable first container containing one or more isocyanatesand a rupturable second container containing one or more polyols,wherein transforming the position-retaining device from the initialconfiguration to an intermediate configuration comprises rupturing thefirst container and rupturing the second container through the casing sothat the one or more isocyanates react with one or more polyols in areaction that forms a polyurethane that surrounds a plurality of beadsand substantially fills the casing, wherein transforming theposition-retaining device from the intermediate configuration to thefinal configuration comprises molding the casing around at least aportion of a body part so that the position-retaining device conforms tothe at least a portion of the body part while the polyurethane is beingformed inside the casing, and wherein after the reaction is finished,the plurality of beads are embedded in the polyurethane so that theposition-retaining device permanently conforms to the at least a portionof the body part.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutepart of this specification, illustrate exemplary embodiments of theinvention, and, together with the general description given above andthe detailed description given below, serve to explain the features ofthe invention.

FIG. 1 is a schematic diagram illustrating a stabilizing cushion in aninitial configuration, according to one embodiment of the presentinvention.

FIG. 2 is a schematic diagram illustrating a stabilizing cushion in anintermediate configuration, according to one embodiment of the presentinvention.

FIG. 3 is a schematic diagram illustrating a stabilizing cushion in afinal configuration, according to one embodiment of the presentinvention.

FIG. 4 is an image of the front of a stabilizing cushion in an initialconfiguration, according to one embodiment of the present invention.

FIG. 5 is an image of the back of the stabilizing cushion of FIG. 4 inthe initial configuration.

FIG. 6 is an image of the stabilizing cushion of FIGS. 4 and 5 beingmolded into a shape in an intermediate configuration.

FIG. 7 is an image of the stabilizing cushion of FIG. 6 in theintermediate configuration .

FIG. 8 is an image of the stabilizing cushion of FIGS. 6 and 7 in afinal configuration.

FIG. 9 is an image of the stabilizing cushion of FIG. 8 molded aroundthe head of an individual.

FIG. 10 is an image of the front of a stabilizing cushion including avent tube in an initial configuration, according to one embodiment ofthe present invention.

FIG. 11 is a close-up of the vent tube of FIG. 10.

FIG. 12 shows the vent tube of FIG. 11 with a removable plug inserted inan open end of the vent tube to prevent liquid from escaping the casingthrough the vent tube.

DETAILED DESCRIPTION OF THE INVENTION Definitions

Where the definition of terms departs from the commonly used meaning ofthe term, applicant intends to utilize the definitions provided below,unless specifically indicated.

It is to be understood that the foregoing general description and thefollowing detailed description are exemplary and explanatory only andare not restrictive of any subject matter claimed. In this application,the use of the singular includes the plural unless specifically statedotherwise. It must be noted that, as used in the specification and theappended claims, the singular forms “a,” “an” and “the” include pluralreferents unless the context clearly dictates otherwise. In thisapplication, the use of “or” means “and/or” unless stated otherwise.Furthermore, use of the term “including” as well as other forms, such as“include”, “includes,” and “included,” is not limiting.

For purposes of the present invention, the term “comprising”, the term“having”, the term “including,” and variations of these words areintended to be open-ended and mean that there may be additional elementsother than the listed elements.

For purposes of the present invention, directional terms such as “top,”“bottom,” “upper,” “lower,” “above,” “below,” “left,” “right,”“horizontal,” “vertical,” “up,” “down,” etc., are used merely forconvenience in describing the various embodiments of the presentinvention. The embodiments of the present invention may be oriented invarious ways. For example, the diagrams, devices, etc., shown in thedrawing figures may be flipped over, rotated by 90° in any direction,reversed, etc.

For purposes of the present invention, a value or property is “based” ona particular value, property, the satisfaction of a condition, or otherfactor, if that value is derived by performing a mathematicalcalculation or logical decision using that value, property or otherfactor.

For purposes of the present invention, it should be noted that toprovide a more concise description, some of the quantitative expressionsgiven herein are not qualified with the term “about.” It is understoodthat whether the term “about” is used explicitly or not, every quantitygiven herein is meant to refer to the actual given value, and it is alsomeant to refer to the approximation to such given value that wouldreasonably be inferred based on the ordinary skill in the art, includingapproximations due to the experimental and/or measurement conditions forsuch given value.

For purposes of the present invention, the term “bead” and the term“beads” refer to any particle that can be embedded in polyurethane. Forexample, a bead of the present invention may be made of any solidmaterial such as plastic, metal, wood, etc. In one embodiment of thepresent invention, the beads of the present invention may be plasticbeads such as polystyrene beads. The beads of the present invention maybe any size that is convenient and any shape that is convenient. Thebeads may be solid, hollow, porous, comprised of a closed-cell foam,such as a closed-cell extruded polystyrene foam such as Styrofoam®, anexpanded plastic such as expanded polystyrene (EPS), etc. The beads mayall be the same size or the beads may be a variety of sizes.

For purposes of the present invention, the term “oleophobic vent” refersto a vent made from an oleophobic material, i.e., an oil-fearingmaterial, that allows the free flow of gases but prevents the flow oflow surface tension fluids and water through the vent. In one embodimentof the present invention, an oleophobic vent may be a piece of a porousoleophobic membrane, i.e., an oleophobic membrane having pores therein,that resists wet-out from low surface tension fluids, such as oil whichhas a surface tension of 30 dynes/cm. An example of a porous oleophobicmembrane is microporous expanded polytetrafluoroethylene (ePTFE)membrane such as the ePTFE membrane marketed under the name GORE™Membrane Vents by W. L. Gore & Associates.

For purposes of the present invention, the term “room temperature”refers to a temperature of from about 20° C. to about 25° C.

For purposes of the present invention, the term “rupturable container”refers to a flexible container, such as a sealed pouch, that may beruptured by hand when the container is filled with a liquid. Arupturable container may including a portion that has been weakened,such as by thinning the material of the container in a region or along aline or pattern. In one embodiment of the present invention, arupturable container maybe a sealed pouch made of aluminum foil, aplastic, etc. that is sufficiently thin that the sealed pouch isrupturable by applying pressure to the sealed pouch through a casingcontaining the sealed pouch when the sealed pouch is filled with aliquid.

Description

In one embodiment, the present invention provides a moldableposition-retaining device which can be made to conform to theconfiguration of a person's body or body part to provide an anatomicallyhigh-accuracy position-retaining device for patient positioning,immobilization, and repositioning during applications requiring a highdegree of accuracy in patient positioning.

A position-retaining device of the present invention may beinterchangeably described as a stabilizing pillow, cushion, cast, orother terms as would be known in the art. A position-retaining devicemay also be part of a larger article such as a headrest, an armrest, achair, a bed, a couch, etc. A position retaining-device of the presentinvention can be used, among other purposes, to retain the person's bodyor body part in a required position or attitude with the pressure fromthe body or body part being distributed such as uniformly andeffectively on the position-retaining device. The device, in certainembodiments, is particularly well-suited for patient positioning duringradiotherapy or other procedures in which high accuracy and consistentrepeatability in positioning are important.

Various types of outfits and equipment have been used in the fields ofmedical treatment and patient care and welfare for stabilizing andsupporting human bodies on beds, chairs, inspection and examinationdevices and the like. With regard to the securing mechanism by whichsuch various outfits and equipment rigidify in conformation with patientbody part, the two primary mechanisms are based on moisture-basedactivation and heat-based application. In the moisture based approach, apredetermined amount of granulated materials coated with a moisturecurable resin is enclosed in a water-permeable container having smalleropenings than the size of the granulated materials. The water-permeablematerial is tightly sealed within a moisture-impermeable container suchas an air-tight aluminum foil to prevent moisture from reaching thecushions. To use the cushion, a therapist will remove the packaging andapply water to the fabric of the cushion. The cushion is then placed andshaped under the patient's head or other body part. The inner resinreacts with the water and hardens in about 10 minutes, creating a solidformed support and stabilizing the patient.

A disadvantage of water-activation methods includes scenarios whereinexcess water may pose a high risk of adversely affecting the medicalinstruments if excess water is present during irradiation by radioactiverays of the spot where many precise instruments are to be placed.Furthermore, in some cases, using moisture-activated securing mechanismproduces an unpleasant scent associated with activation of the productand, furthermore, it feels sticky to touch. The impracticality ofheating the securing process requires an oven, or a hot water bath whichmay not always be available.

Heat-based approaches using thermoplastics for patient positioning hasbeen described. These position-retaining devices are similarlyconstructed as their moisture-activated counter-parts but with adifferent method of becoming secure. These devices generally comprise aninner component of small beads surrounded by a layer of thermoplasticmaterial, such as polycaprolactone, that softens and becomes moldable athigh temperatures (target temperature depending on the thermoplasticcompound). The thermoplastic layer typically has a soft fabric materialsurrounding it, for patient comfort. Such a device much first be placedin an oven, or in a hot water bath to heat it to desired temperature atwhich the device becomes moldable by hand and remains moldable for shortperiod of time. The device remains moldable for a period of timetypically in range of 5 to 8 minutes as it cools to room temperature.The position-retaining device hardens to create a firm support cushion,conforming to and stabilizing the patient.

Embodiments of the present invention address the above shortcomings ofcurrent position-retaining patient immobility devices by providing asecuring mechanism that does not require application of water or heat.

In one embodiment, the present invention provides a moldable stabilizingcushion includes a casing containing beads, such as polystyrene beads,that constitute a deformable inner body of the moldable stabilizingcushion. To bind the beads together and fix the position of the beads inplace after the moldable stabilizing cushion has been molded to adesired shape, in an initial configuration, the moldable stabilizingcasing contains a two-part binding agent in addition to the beads. Thetwo-part binding agent consists of one rupturable container containingone or more isocyanates and a second rupturable container containing oneor more polyols. When the two rupturable containers are ruptured, suchas by rupturing the rupturable containers by hand through the casing,the one or more isocyanates and the one or more polyols are released andmix to form a polyurethane that expands to fill or substantially fillthe casing and surround the beads. While the polyurethane is beingformed and before the polyurethane hardens, the moldable stabilizingcushion is in an intermediate configuration that allows the moldablestabilizing cushion to be molded into a desired shape. After period oftime, the polyurethane hardens and the beads are fixed in place so thatthe moldable stabilizing cushion achieves a final configuration.

In one embodiment of the present invention, while the moldablestabilizing cushion is an intermediate configuration, the moldablestabilizing cushion may be molded around a body part or a portion of abody part so that in the final configuration the moldable stabilizingcushion conforms to the shape of the body part or the portion of thebody part and may be used to support the body part or the portion of thebody part.

In one embodiment of the present invention, the transformation of themoldable stabilizing cushion from the initial configuration to theintermediate configuration may be achieved by application of pressureupon outer walls of one or more rupturable containers contained in thecasing to thereby cause the reagents in the one or more rupturablecontainers to be released into the space in between and around thebeads.

A two-part polyurethane that may be used in various embodiments of thepresent invention is formed from the reaction of a monomeric orpolymeric isocyanate with a polyol. Isocyanates suitable for thepurposes of the present invention include one or more isocyanate (NCO)functional groups, typically at least two NCO functional groups.Suitable isocyanates include, but are not limited to, conventionalaliphatic, cycloaliphatic, aryl and aromatic isocyanates. Some morespecific examples include diphenylmethane diisocyanates (MDIs),polymeric diphenylmethane diisocyanates (PMDIs), and combinationsthereof. Polymeric diphenylmethane diisocyanates may be also referred toas polymethylene polyphenylene polyisocyanates. Examples of othersuitable isocyanates include, but are not limited to, toluenediisocyanates (TDIs), hexamethylene diisocyanates (HDIs), isophoronediisocyanates (IPDIs), naphthalene diisocyanates (NDIs), andcombinations thereof

Suitable polyols for the purposes of the present invention includes oneor more hydroxyl (ROH) functional groups, or more specifically at leasttwo hydroxyl functional groups. A polyol can be any type of polyol. Someexamples of suitable polyols include, but are not limited to, ethyleneglycol, diethylene glycol, propylene glycol, dipropylene glycol,butanediol, glycerol, trimethylolpropane, triethanolamine,pentaerythritol, sorbitol, and combinations thereof

FIG. 1 illustrates an initial configuration 100 for position-retainingdevice 102 according to one embodiment of the present.Position-retaining device 102 includes a casing 104 containing beads 106and a two-part urethane system 108 consisting of an isocyanate component110 contained within a rupturable container 112 and a polyol component114 contained in a rupturable container 116. Isocyanate component 110may be a single isocyanate or may be a mixture of two or moreisocyanates. Polyol component 114 may be a single polyol or may be amixture of two or more polyols. In this configuration two-part urethanesystem 108 is inactive, beads are free to move in casing 104 andposition-retaining device 102 may be stored until it is ready for use.

In one embodiment the beads may puffed or non-puffed polystyrene beadhaving a density form 1 to 5 lb/ft³ per cubic foot (16.02 to 80.09kg/m³).

Although for simplicity of illustration, the rupturable containers areshown in FIG. 1 as being near the top of the moldable position-retainingdevice and in the center of the position-retaining device. However, inother embodiments of the present invention, the rupturable containersmay be located elsewhere within the casing. The two rupturablecontainers may be located closely together, or even adjacent, as shown,or may be located a distance away from each other in the casing. In oneembodiment of the present invention, the rupturable containers may beconnected to each other. In one embodiment of the present invention, therupturable containers may be connected to a prescribed location withinthe casing, such as at one end of the casing, so that the two rupturablecontainers may be easily located. In one embodiment of the presentinvention, there may be two or more rupturable containers for theisocyanate component and two or more rupturable containers for thepolyol component. In one embodiment of the present invention, two ormore rupturable containers may each contain a different isocyanate. Inone embodiment of the present invention, two or more rupturablecontainers may contain different polyols.

FIG. 2 shows position-retaining device 102 in an intermediateconfiguration 200 when two-part urethane system 108 is activated byrupturing rupturable container 112, as shown by rupture 212, and byrupturing rupturable container 116, as shown by rupture 216. Uponrupturing, isocyanate component 110 flows from rupturable container 112,as indicated by arrows 220, and mixes with polyol component 114 flowingfrom rupturable container 116, as indicated by arrows 224. As isocyanatecomponent 110 and polyol component 114 mix together and react to form apolyurethane, the polyurethane so formed flows around and between beads106 and fills or substantially fills casing 104. As the polyurethane isbeing formed, position-retaining device 102 is in the process of beingmolded by hand around a portion 242 of a body part 244.

The position-retaining device remains deformable for a period ofapproximately 5 to 10 minutes while in the intermediate condition.During this period of time, the stabilizing may be molded by hand toconform and/or surround a body part or a portion of a body part. Exampleof body parts and portions of body parts to which the position-retainingdevice may be conformed or support including an individual's arm, leg,hand, foot, finger or fingers, toe or toes, thigh, calf, ankle, wrist,elbow, knee, head, jaw, back, spine, torso, hip, chest, etc.

The rupturable containers may be ruptured in a variety of ways includingby applying pressure to the casing in a single direction to press thecasing against a solid surface, such as a table, or by squeezing thecasing. The rupturable containers may also be ruptured by using a deviceto apply pressure in a single direction to the casing against a solidsurface, such as a table, or to squeeze the casing.

FIG. 3 shows position-retaining device 102 in a final configuration 300in which a polyurethane 312 formed by the reaction of isocyanatecomponent 110 and polyol component 114 fills or substantially fillscasing 104. In final configuration 300, position-retaining device 102has been molded by hand around portion 242 of body part 244. Beads 106embedded in polyurethane 312 provide a light, low density and moldableinternal body that helps hold the shape of position-retaining device 102during the molding of position-retaining device 102 whileposition-retaining device 102 is in intermediate configuration 200 andhelps maintain the shape of position-retaining device 102 in finalconfiguration 300. Polyurethane 312 surrounding beads 106 locks beads106 in place, thereby further helping to maintain the shape ofposition-retaining device 102 in final configuration 300. In finalconfiguration 300, position-retaining device 100 has a relatively stableshape that conforms to portion 242 of body part 244 and supports bodypart 244. Now empty rupturable container 112 and rupturable container116 remain in position-retaining device 102 and become part of thehardened matrix.

In one embodiment, the rupturable containers may be thin and flimsy sothat the empty rupturable containers do not significantly affect theshape of the position-retaining device.

The casing may be made of a woven fabric material of natural and/orsynthetic fibers such cotton, silk, nylon, rayon, polyester, mixtures offibers, etc. The casing may include a liner or may be made of multiplelayers. In one embodiment, the casing may include a pull liner.

The rupturable container containing the isocyanate may be a made from aflexible material that is impervious to moisture such as aluminum,because the isocyanate component may react with water. In one embodimentof the present invention, the rupturable container containing theisocyanate may be rupturable sealed pouch made of aluminum foil with,for example, a very low moisture vapor transit rate.

The rupturable container containing the polyol may be a made from avariety of materials, such as plastics, that may or may not beimpervious to moisture. In one embodiment of the present invention, therupturable container containing the polyol component may be rupturablesealed pouch made of a plastic such a polyethylene, including highdensity polyethylene and low density polyethylene, polypropylene,polyvinylidene chloride, etc. In one embodiment, the rupturablecontainer for the polyol may be made from a foil pouch or a foil-linedpouch that has a very low moisture vapor transit rate so that therupturable container is a virtually moisture proof barrier.

The beads may be made of materials such as plastic, rubber, metal, wood,etc., that may be rigid or at least partially deformable. In oneembodiment, the beads may be made of a non-puffed material. In oneembodiment of the present invention, the beads may be made of relativelyrigid plastic such as polystyrene, etc. The particular size and densityof the beads used may vary depending on the particular application thatthe position-retaining device is used. The beads may have various shapessuch as spherical, rod-shaped, cube-shaped, bar-shaped,cylindrically-shaped, star-shaped, toroidal, ovoid-shaped, V-shaped,L-shaped, I-beam-shaped, disk-shaped, pyramid-shaped, etc. In oneembodiment of the present invention, the beads do not have sharp edgesor corners to prevent the beads from damaging the rupturable containersand the casing and to ensure that the position-retaining device does notirritate the body part or portion of body part in contact with theposition-retaining device. The beads may solid or hollow. In someembodiments, the beads may made of a foamed material such as expandedpolystyrene (EPS) or a closed-cell extruded polystyrene foam, e.g.,Styrofoam®, to make the position-retaining device wider and/or toprovide the position-retaining device with additional deformability andsoftness. In embodiments of the present invention where durability isimportant, a harder bead may be used.

In accordance to one embodiment of the present invention, the casing mayinclude one or more oleophobic vents that allow gases, such as carbondioxide (CO₂), to escape the casing but which do not allow any reagentsor reagent mixtures to escape. The oleophobic vents facilitate removalof any gaseous by-product of the two-part polyurethane formation suchas, for example, CO₂ that may be produced during the chemical reactionbetween the isocyanate component and the polyol component of theposition-retaining device. Without the oleophobic vents, released gasesmay accumulate within the casing which may cause a balloon-typesituation that allows too much movement of the patient and defeats thepurpose of stabilization. The oleophobic vents will allow gasses (suchas CO₂) to escape but not liquid such as, for example the chemicalcompositions or reagents used for binding and securing the internalmoldable body of beads. In one embodiment, the oleophobic vents may havepores that are 0.5 to 5.0 μm in diameter.

An example of a position-retaining device, a stabilizing cushion,according to one embodiment of the present invention having oleophobicvents in the casing is shown in FIGS. 4, 5, 6, 7, 8 and 9.

FIG. 4 and FIG. 5 respectively illustrate a front and a back view ofstabilizing cushion 402 in an initial configuration. Stabilizing cushionhas a casing 404 having oleophobic vents 406. Casing 404 contains beads(not visible), a sealed aluminum pouch containing an isocyanate (notvisible in FIGS. 4 and 5), and a sealed foil lined pouch containing apolyol (not visible). By squeezing on stabilizing cushion 402, thesealed pouch containing the isocyanate and the sealed pouch containing apolyol are ruptured, thereby allowing the isocyanate and polyol to reactwith each other to form a polyurethane that flows around beads. As thepolyurethane is being form, stabilizing cushion 402 is molded into anintermediate configuration shown in FIG. 6 and FIG. 7.

FIG. 8 shows stabilizing cushion 402 in a final configuration in whichthe polyurethane has sufficiently filled casing 404 to lock the beads inplace. FIG. 9 shows stabilizing cushion 402 molded around a portion 912,i.e., the back, of an individual's head 914. In one embodiment of thepresent invention, the stabilizing pillow may be utilized as anaccessory to radiation therapy systems as a stand-alone device or inconjunction with a thermoplastic mask

In accordance to one embodiment of the present invention, the casing mayinclude one or more vent tubes that allow gases, such as carbon dioxide(CO₂), to escape the casing. To prevent reagents or reagent mixturesfrom escaping the casing, each vent tube may be plugged by a removableplug inserted in an open end of the vent tube. The removable plug may beremoved after the reaction of reagent mixtures have started. One or morevent tubes may be used instead of oleophobic vents or in addition tooleophobic vents to allow gases to escape the casing. The vent tubesfacilitate removal of any gaseous by-product of the two-partpolyurethane formation such as, for example, CO₂ that may be producedduring the chemical reaction between the isocyanate component and thepolyol component of the position-retaining device. The one or more venttubes prevent released gases that may accumulate within the casing fromcausing a balloon-type situation that allows too much movement of thepatient and defeats the purpose of stabilization. The one or more venttubes allow gasses (such as CO₂) to escape after the removable plug isremoved from the vent tube. Prior to the removable plug being removedfrom a vent tube, liquids such as, for example the chemical compositionsor reagents used for binding and securing the internal moldable body ofbeads are prevented from escaping from the casing by the removable plug.

In one embodiment of the present invention, instead of a removable plug,an open end of each vent tube may be covered by a removable cap to closeor seal the vent tube in an initial configuration of the stabilizingcushion. In one embodiment of the present invention, each vent tube maybe closed or sealed in an initial configuration of the stabilizingcushion and the one or more vent tubes may be opened by puncturing anend of each of the vent tubes, cutting off an end of each of the venttubes, breaking of a sealed end of the vent tube from the rest of thevent tube at a weakened or frangible portion of the vent tube, etc.

An example of a position-retaining device, a stabilizing cushion,according to one embodiment of the present invention having a vent tubeextending from the casing is shown in FIGS. 10, 11 and 12.

FIGS. 10, 11 and FIG. 12 respectively show a stabilizing cushion 1002 inan initial configuration. Stabilizing cushion has a casing 1004 havingvent tube 1006. Casing 1004 contains beads (not visible), a sealedaluminum pouch containing an isocyanate (not visible in FIGS. 10, 11 and12), and a sealed foil lined pouch containing a polyol (not visible). Bysqueezing on stabilizing cushion 1002, the sealed pouch containing theisocyanate and the sealed pouch containing a polyol are ruptured,thereby allowing the isocyanate and polyol to react with each other toform a polyurethane that flows around beads. FIG. 12 shows a removableplug 1202 inserted in an open end 1204 of vent tube 1006 to preventliquids from escaping casing 1004 through vent tube 1006.

Having described the many embodiments of the present invention indetail, it will be apparent that modifications and variations arepossible without departing from the scope of the invention defined inthe appended claims. Furthermore, it should be appreciated that allexamples in the present disclosure, while illustrating many embodimentsof the invention, are provided as non-limiting examples and are,therefore, not to be taken as limiting the various aspects soillustrated.

All documents, patents, journal articles and other materials cited inthe present application are incorporated herein by reference.

While the present invention has been disclosed with references tocertain embodiments, numerous modification, alterations, and changes tothe described embodiments are possible without departing from the sphereand scope of the present invention, as defined in the appended claims.Accordingly, it is intended that the present invention not be limited tothe described embodiments, but that it has the full scope defined by thelanguage of the following claims, and equivalents thereof.

What is claimed is:
 1. A device comprising a casing and having: an initial configuration, an intermediate configuration, and a final configuration, wherein in the initial configuration the casing contains: a plurality of beads, a rupturable first container containing one or more isocyanates and a rupturable second container containing one or more polyols, wherein in the final configuration the casing is substantially filled by a polyurethane in which the plurality of beads are embedded, wherein in the intermediate configuration the device is transformed from the initial configuration to the final configuration by rupturing the first container and rupturing the second container so that the one or more isocyanates react with the one or more polyols in a reaction that forms the polyurethane, and wherein as the polyurethane is formed during the reaction the polyurethane surrounds the plurality of beads.
 2. The device of claim 1, wherein the device is in the initial configuration.
 3. The device of claim 1, wherein the device is in the final configuration.
 4. The device of claim 1, wherein the device is configured so that the device can be transformed from the initial configuration to the intermediate configuration by application of pressure upon the first container and the second container, respectively, through the casing.
 5. The device of claim 1, wherein the casing comprises a fabric material.
 6. The device of claim 5, wherein the fabric material includes one or more vents configured to allow gases formed by the reaction to escape the casing but prevent liquids from escaping the casing.
 7. The device of claim 6 wherein the vents have pores that are 0.2 to 5.0 μm in diameter.
 8. The device of claim 5, wherein the casing includes one or more vent tubes configured to allow gases formed by the reaction to escape the casing.
 9. The device of claim 1, where wherein the first container is comprises of a material that is impervious to moisture.
 10. The device of claim 9, wherein the first container comprises an aluminum pouch.
 11. The device of claim 1, wherein the second container comprises a plastic pouch.
 12. The device of claim 1, wherein the plurality of beads comprise polystyrene beads.
 13. The device of claim 1, wherein the device comprises a stabilizing pillow.
 14. A method comprising: transforming a position-retaining device from an initial configuration to an intermediate configuration, and transforming the position-retaining device from the intermediate configuration to a final configuration, wherein in the initial configuration, the position-retaining device comprises a casing containing: a plurality of beads, a rupturable first container containing one or more isocyanates and a rupturable second container containing one or more polyols, wherein transforming the position-retaining device from the initial configuration to an intermediate configuration comprises rupturing the first container and rupturing the second container through the casing so that the one or more isocyanates react with one or more polyols in a reaction that forms a polyurethane that surrounds a plurality of beads and substantially fills the casing, wherein transforming the position-retaining device from the intermediate configuration to the final configuration comprises molding the casing around at least a portion of a body part so that the position-retaining device conforms to the at least a portion of the body part while the polyurethane is being formed inside the casing, and wherein after the reaction is finished, the plurality of beads are embedded in the polyurethane so that the position-retaining device permanently conforms to the at least a portion of the body part.
 15. The method of claim 14, wherein the first container and the second container are each ruptured by application of pressure upon the first container and the second container, respectively, through the casing.
 16. The method of claim 14, wherein the casing comprises a fabric material.
 17. The method of claim 16, wherein the fabric material includes one or more vents configured to allow gases formed by the reaction to escape the casing but prevent liquids from escaping the casing.
 18. The method of claim 17 wherein the vents have pores that are 0.2 to 5.0 μm in diameter.
 19. The method of claim 16, wherein the fabric material includes one or more vent tubes configured to allow gases formed by the reaction to escape the casing.
 20. The method of claim 14, where wherein the first container is comprised of a material that is impervious to moisture.
 21. The method of claim 20, wherein the first container comprises an aluminum pouch.
 22. The method of claim 14, wherein the second container comprises a plastic pouch.
 23. The method of claim 14, wherein the plurality of beads comprise polystyrene beads.
 24. The method of claim 14, wherein the position-retaining device comprises a stabilizing pillow.
 25. A product comprising the position-retaining device of claim 14 in the final configuration. 